1. Field of the Invention
The present invention relates to metal detectors.
2. Background
Improvised explosive devices (IEDs) are a problem in some war zones. Commonly, the IED is a bomb made of any type of available ordnance, for example, a cluster of mortar shells, a single artillery shell or multiple artillery shells. The IED is usually placed next to a road and camouflaged, for example by rocks, or buried in the ground. The IED is then detonated by remote control when a vehicle drives nearby.
A need exists to detect IEDs safely, but metal detection is a short range sensing technology using conventional metal detector sensor methods such as magnetic anomaly detection (MAD) and electromagnetic induction (EMI). The problem to be solved is to detect metal from many tens of meters away to avoid an IED explosion in safety while placing a sensor near enough to the IED to permit its detection and neutralization.